1. Field of the Invention
The present invention relates generally to apparatus for blast cleaning surfaces, and particularly to a machine for blast cleaning surfaces disposed at angles within approximately 45 degrees of vertical.
2. Description of Related Art
Various apparatus for blast cleaning vertical surfaces are known in the art. For example, U. S. Pat. No. 3,900,969 issued to Diehn discloses a portable apparatus for blast cleaning. If the Diehn machine is rotated 45 degrees from vertical, the path of abrasive material from the hopper to the blast wheel includes a horizontal portion which prevents gravity feed of the abrasive material. Accordingly, an apparatus like the Diehn machine cannot be used effectively to blast clean curved structures such as water towers and ship hulls.